From the blog "My creations"

This is TRX futa addon version of ERF blender file for creating seamles textures patches.     Now you can make textures compability patch for any body textures package. and TRX futa addon TRX_seamless_sample.blend     My big thanks and all credits for original tool and brilliant idea to EvilReFlex   Method of textures patching is completely the same, so you can read all instructions in original topic Easy way to make seamless SOS Textures. I stro